Real-World Outcomes of Fourth-Generation Mitral Transcatheter Repair: 30-Day Results From EXPAND G4

Background: The fourth-generation MitraClip G4 System builds on the previous NTR/XTR system with additional wider clip sizes (NTW and XTW), an independent grasping feature, and an improved clip deployment sequence. Objectives: The primary objective of this study was to assess the safety and performance of the MitraClip G4 System within a contemporary real-world setting. Methods: EXPAND G4 is a prospective, multicenter, international, single-arm, postapproval study that enrolled patients with primary (degenerative) mitral regurgitation (MR) and secondary (functional) MR at 60 centers. Follow-up of the full cohort has been conducted through 30 days. Echocardiograms were analyzed by an echocardiography core laboratory. Study outcomes included MR severity, functional capacity measured by NYHA functional class, quality of life measured using the Kansas City Cardiomyopathy Questionnaire, major adverse event rates, and all-cause mortality. Results: In EXPAND G4, 1,141 subjects with primary MR and secondary MR were treated from March 2021 to February 2022. Implantation and acute procedural success rates were 98.0% and 96.2%, respectively, with a mean of 1.4 ± 0.6 clips implanted per subject. MR was significantly reduced at 30 days compared with baseline (98% achieved MR ≤ 2+, and 91% achieved MR ≤ 1+; P < 0.0001). Functional capacity and quality of life were substantially improved, with 83% of patients achieving NYHA functional class I or II. Likewise, an 18-point improvement was observed in Kansas City Cardiomyopathy Questionnaire summary scores compared with baseline. The composite major adverse event rate was 2.7%, and the all-cause death rate was 1.3% at 30 days. Conclusions: This study demonstrates for the first time the effectiveness and safety of MitraClip G4 System at 30 days in a cohort of >1,000 patients with MR in a contemporary, real-world setting.